This invention concerns certain polyfluoro-iodoethoxy compounds, a process therefor, and monomer derivatives thereof. The following publications are representative of the state of the art on polyfluoro-iodoethoxy compounds.
U.S. Pat. Nos. 4,275,226 and 4,340,750 disclose the reaction, XR.sub.F COF+C.sub.2 F.sub.4 +MF+I.sub.2 .fwdarw.XR.sub.F CF.sub.2 OCF.sub.2 CF.sub.2 I, where X is H, Cl, Br, F, CO.sub.2 R, --COF, SO.sub.2 F, CONRR' or P(O)(OR).sub.2 ; R.sub.F is C.sub.1 to 20 difunctional perfluoro-containing group which can have one or more ether bonds; R is C.sub.1 to 10 alkyl, R' is H or C.sub.1 to 10 alkyl; M is K, Rb or Cs. The compounds CH.sub.3 O.sub.2 C(CF.sub.2).sub.n CF.sub.2 OCF.sub.2 CF.sub.2 I, where n is 1, 2 or 4 are disclosed but not how to make them. Vinyl ethers devoid of iodine are prepared from the iodo compounds by heating in a solvent in the presence of selected metals: XR.sub.F CF.sub.2 OCF.sub.2 CF.sub.2 I.fwdarw.XR.sub.F CF.sub.2 OCF.dbd.CF.sub.2.
U.S. Pat. No. 3,311,658 discloses the compound, FOCCF(CF.sub.3)[OCF.sub.2 CF(CF.sub.3)].sub.m O(CF.sub.2).sub.n+1 I, and its pyrolysis to the vinyl ether, CF.sub.2 .dbd.CF[OCF.sub.2 CF(CF.sub.3)]mO(CF.sub.2).sub.n+1 I, where m is 0 to 5 and n is 1 to 8, preferably 1 or 3. The .omega.-iodoacyl fluoride is prepared by reacting the compounds FOC(CF.sub.2).sub.n I with hexafluoropropene oxide (HFPO).
GB No. 2,056,445A discloses preparation of an .omega.-(2-iodoethoxy)acyl fluoride, FOC(CF.sub.2).sub.n OCF.sub.2 CF.sub.2 I, where n is 1 to 8, by reacting a perfluorinated lactone and/or a perfluorodiacyl fluoride with tetrafluoroethylene, an iodine source such as I.sub.2 or ICl, and fluoride ion in an aprotic solvent. The lactone can be prepared from the compound, FOC(CF.sub.2).sub.2-4 I.
Evans et al., J. Org. Chem. 33 (5), 1839 (1968) disclose that I.sub.2 or ICl can be used in the reaction of perfluorinated ketones with fluoroolefins in the presence of fluoride ions to form .omega.-(2-iodoethoxy) compounds. However, when the fluoroolefin is tetrafluoroethylene, details are limited to: XCF.sub.2 C(O)CF.sub.3 +KF+C.sub.2 F.sub.4 +I.sub.2 .fwdarw.XCF.sub.2 CF(CF.sub.3)OCF.sub.2 CF.sub.2 I wherein X is F or Cl.
U.S. Pat. No. 4,335,255 discloses fluorinated ketoesters of the formula, RO.sub.2 CCF(CF.sub.3)OCF.sub.2 C(O)CF.sub.3, and HFPO adducts thereof, RO.sub.2 CCF(CF.sub.3)OCF.sub.2 CF(CF.sub.3)O[CF(CF.sub.3)CF.sub.2 O].sub.n CF(CF.sub.3)COF, wherein n is 0 to 6.
U.S. Pat. No. 4,390,720 discloses alkyl-.omega.-fluoroformyl esters of the formula, RO.sub.2 C--CF(CF.sub.3)O[CF(CF.sub.3)CF.sub.2 O].sub.n CF(CF.sub.3)COF, wherein n is 0 to 3.
U.S. Pat. No. 4,153,804 discloses .omega.-fluoroformyl esters of the formula, RO.sub.2 C(R.sub.F).sub.m [CF.sub.2 OCF(CF.sub.3)].sub.n COF, wherein R.sub.F is C.sub.1 to 10 bifunctional perfluoro group, m is 0 or 1, n is 1 to 5 and R is alkyl, prepared by reacting acyl fluorides of the formula, RO.sub.2 C(R.sub.F).sub.m COF, with HFPO.
U.S. Pat. No. 4,032,566 discloses the reaction, CH.sub.3 O.sub.2 C--R.sub.F --CF(CF.sub.3)COF+C.sub.2 F.sub.4 +KF+ICl.fwdarw.CH.sub.3 O.sub.2 C--R.sub.F CF(CF.sub.3)CF.sub.2 OCF.sub.2 CF.sub.2 I, wherein R.sub.F is --(CF.sub.2).sub.4 O[CF(CF.sub.3)CF.sub.2 O].sub.n or --CF(CF.sub.3)OCF.sub.2 CF.sub.2 O--, and n is 0 to 10. Also disclosed is a similar reaction employing a diacyl fluoride in place of an ester-acyl fluoride: FOCCF(CF.sub.3)OCF.sub.2 CF.sub.2 OCF(CF.sub.3)COF+C.sub.2 F.sub.4 +KF+ICl FOCCF(CF.sub.3)OCF.sub.2 CF.sub.2 OCF(CF.sub.3)CF.sub.2 OCF.sub.2 CF.sub.2 I. Reaction of this acyl fluoride product with methanol to form the corresponding ester is described.
U.S. Pat. No. 3,351,619 discloses copolymerization of certain vinyl ethers disclosed in U.S. Pat. No. 3,311,658 with halogenated .alpha.-olefins, including TFE, vinylidene fluoride, perfluoromethylvinyl ether and chlorotrifluoroethylene to form melt-fabricable, (iodo)cross-linkable polymers.
U.S. Pat. No. 4,243,770 discloses cross-linkable fluorinated polymers containing 0.001 to 10 weight percent of chemically-bound iodine, prepared by polymerizing vinylidene fluoride and, optionally, other fluoromonomers in the presence of a fluorinated iodo compound.
U.S. Pat. No. 4,251,399 discloses cross-linkable polymer blends comprising an iodine-containing fluoroelastomer prepared as in U.S. Pat. No. 4,243,770.
Japanese Application No. J56/72,002 discloses preparation of fluorinated polymers containing pendant groups of the formula, --O[CF(CF.sub.3)CF.sub.2 O].sub.p (CF.sub.2).sub.q I, where p is 0 to 5 and q is 1 to 10, by reacting a fluorinated polymer containing pendant groups of the formula --O[CF(CF.sub.3)CF.sub.2 O].sub.p (CF.sub.2)CO.sub.2 H with I.sub.2 or I-containing compound in the presence of peroxide.
Japanese Patent Application Nos. J56-95924, J56-95925 and J56-95926 disclose the preparation of crosslinkable fluorinated cation exchange membranes by treating membranes containing pendant --O(CF.sub.2).sub.n A groups to convert at least some of said groups to iodo-functional groups --O(CF.sub.2).sub.n I; A includes --COF, --CO.sub.2 R and --CO.sub.2 M where R is C.sub.1 to 10 alkyl and M is an alkali metal or ammonium.
Japanese Patent Appplication No. J53-125986 discloses the conversion, in fluorinated polymeric membranes, of pendant --OCF.sub.2 CF.sub.2 I groups to --OCF.sub.2 CO.sub.2 M groups having ion exchange properties (M is metal or ammonium) by means of heat, uv irradiation and/or treatment with chemical reagents such as peroxides, strong sulfur or nitric acids, or amines.
Japanese Patent Application No. J53-131292 discloses the conversion, in fluorinated polymeric membranes, of pendant --CF.sub.2 I groups to --CO.sub.2 M groups having ion-exchange properties by treatment with an organometallic halide such as magnesium methyl bromide, followed by a reagent such as CO.sub.2, COF.sub.2, PX.sub.3 or POX.sub.3 where X is halogen.